They caught me by surprise a couple times.
One time in the demo, walking down a short hallway, being careful of ambushes and scary stuff and the scary music starts up. I think "oh, Alma's going to pop out from the area on the right behind that thing!" I turn on the flashlight, look and she's not there. Scary music still going on. I look to the left. Not there. "Maybe she's up ahead? Or did I miss her?"
I turn around and hit every single button that's assigned an attack. I melee, grenade, fire. Almost all at once. Because there's Alma, right behind me, the entire time.